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/*
* rwlock6.c
*
* Check that writer locks have priority.
*
* Depends on API functions:
* pthread_rwlock_rdlock()
* pthread_rwlock_wrlock()
* pthread_rwlock_unlock()
*/
#include "test.h"
#define PRTDEBUG(M, F, L) {FILE * fp; fp = fopen("debug.log", "a"); fprintf(fp, "%s: %s: %d\n", M, F, L); fclose(fp);}
static pthread_rwlock_t rwlock1 = PTHREAD_RWLOCK_INITIALIZER;
static int bankAccount = 0;
void * wrfunc(void * arg)
{
assert(pthread_rwlock_wrlock(&rwlock1) == 0);
//PRTDEBUG("wr", __FILE__, __LINE__);
Sleep(2000);
bankAccount += 10;
assert(pthread_rwlock_unlock(&rwlock1) == 0);
return ((void *) bankAccount);
}
void * rdfunc(void * arg)
{
int ba = 0;
assert(pthread_rwlock_rdlock(&rwlock1) == 0);
//PRTDEBUG("rd", __FILE__, __LINE__);
ba = bankAccount;
assert(pthread_rwlock_unlock(&rwlock1) == 0);
ba += 10;
return ((void *) ba);
}
int
main()
{
pthread_t wrt1;
pthread_t wrt2;
pthread_t rdt;
int wr1Result = 0;
int wr2Result = 0;
int rdResult = 0;
bankAccount = 0;
assert(pthread_create(&wrt1, NULL, wrfunc, NULL) == 0);
Sleep(500);
assert(pthread_create(&rdt, NULL, rdfunc, NULL) == 0);
Sleep(500);
assert(pthread_create(&wrt2, NULL, wrfunc, NULL) == 0);
assert(pthread_join(wrt1, (void **) &wr1Result) == 0);
assert(pthread_join(wrt2, (void **) &wr2Result) == 0);
assert(pthread_join(rdt, (void **) &rdResult) == 0);
assert(wr1Result == 10);
assert(wr2Result == 20);
printf("rdResult = %d\n", rdResult);
fflush(stdout);
assert(rdResult == 30);
return 0;
}
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